Processing of cocoa beans



Aug. 31, 1954 A. E. slEHRs PROCESSING oF cocoA BEANS 2 Sheets-Sheet lFiled March 21, 1952 "vult INVENTOR. E SIEHFQS BY dY/'y 1 HTTOPNEYS...Ew ooo.

EOQOQ uvt/NIN 3 ...6.6. So. .5S `:ou SL ovou wenzm 2 Sheets-Sheet 2QT'T'O ENEYS Aug, 3l, 1954 A. E. slEHRs PROCESSING oF cocoA BEANS Filedmarch 21, 1952 l l 1 1 11 /1 1/ 11 l f, f f,

Patented ug. 31, 1954 PROCESSING F COCOA BEANS Arthur il. Siehrs,Chicago, Ill., assignor to Krim'- Ko Corporation, Chicago, Ill., acorporation of Illinois Application March 21, 1952, Serial No. 277,787

l1 Claims. l

This invention relates to the treatment of cocoa, chocolate liquor,cocoa beans or nibs in the production of cocoa ilavoring for chocolateSyrups, and the like. It has particularly reference to an improvedprocess by which the cocoa flavoring is obtained substantially free fromcooca butter, and the latter is extracted in a practically Dure form.

Cocoa beans have a substantial fat content in the form of cocoa butter.Cocoa beans, nibs, chocolate liquor, and cocoa contain varying amountsof cocoa butter ranging from 55% in beans to 8 or 9% in the lowestnormally produced low fat cocoas. While the present process can be usedwith slight modification to remove the cocoa butter from beans, nibs,liquor or cocoa, the invention will be described for illustrativepurposes in connection with the removal of cocoa butter from cocoa. Inthe manufacture of chocolate flavored products such as chocolateflavored syrup or beverages, it is desirable to obtain the chocolateflavoring as free as possible from cocoa butter or fat. The fat does notimprove the lavoring value of the material for chocolate syrups, and itspresence in substantial amounts is apt to impair the keeping quality ofthe product. Moreover, the fat when extracted as cocoa butter is ofconsiderable value commercially.

The starches in raw cocoa have a particularly strong aiiinity for thefatty materials, which accounts at least in part for the diculty ineiecting even approximately complete extraction of the cocoa butter. Ithas long been known that the fatty material held in the cocoa can belargely released by heating an aqueous mixture of the finely dividedcocoa to gelatinize the insoluble starch, and then saccharifying thegelatiniz'ed starch by an enzymatic action so that it is brought intosolution. The liberated fatty material or oil is lighter than the otherconstituents of the mixture; and it has been proposed heretofore toseparate it from the other constituents by gravity settling orcentrifugation, or by a combination of these expedients. For example,Hocker Patents Nos. 1,650,355 and 1,650,356 (dated November 22, 1927)and 1,680,943 (dated August 14, 1928) disclose various techniquesutilizing gravity for separating the oil; Hocker Patent No. 1,751,331(dated March 18, 1930) discloses centrifugal separation by successivelyparing the oil and then the other constituents from a centrifugal bowl;and Hocker Patents Nos. 1,803,615 (dated May 5, 1931) and 1,882,013(dated October 1,1, 1932) disclose separations utilizing various 2combinations of the gravity and centrifugal techniques.

However, these prior proposals leave much to be desired, both in economyof operation and in the quality of the products. Gravity settling, evenwith liberation of CO2 as proposed by Hocker, is too time-consuming forgood commercial practice and does not enable a clean separation. rBheuse of centrifugal separation as disclosed by Hockerrequires a carefulparing of the separated components in succession from the centrifugalbowl, and in most cases is dependent upon a Jpreliminary gravitysettling. A major difficulty in the centrifugal separation of thematerial is the relatively small spread `oetween the specic gravities ofthe cocoa butter oil and the other liquid Constituents, and the strongtendency for the oil and water to form an emulsion which carries some ofthe other materials and is difcult to separate. In an effort tofacilitate the separation, Hocker proposes to add sugar to the mixtureprior to the centrifuging, to increase the specic gravity of the heavierliquid relative to that of the oil; but the large quantity of sugarrequired for any appreciable effect in this respect causes such anincreased loading of the system as to substantially nullify itsadvantages. Further, it requires a,y long period of heating, whichgreatly decreases the ilavor value of the resulting products and greatlyincreases the bacterial hazard.

According to the present invention, the insoluble starches in the cocoaare gelatinized by heating an aqueous solution of the cocoa, and arethen subjected to an enzymatic saccharication to liberate the cocoabutter or oil. After addition of a protein-coagulating agent, such ascommon salt, the mixture is fed continuously through a centrifugal bowl(locus of centrifugal force) where it is separated into an oil and watercomponent and a substantially oil-free component. I do not attempt inthis separation to obtain even an approximately pure oil. Instead, thecentrifuge is adjusted to separate practically all of the oil from themain body of insoluble cocoa solids (sludge) and the watery extract ofsoluble cocoa solids, and in suchv separation some of the extract andpossibly some of the solids will necessarily accompany the oil and thewater with which it is emulsied. Since the mixture undergoing thiscentrifugation will normally contain all of the original oil content ofthe cocoa, there will be a substantial quantity of oil to act as anucleus for the separation of the oil from the main extract and sludge.

The substantially oil-free component and the oil and water component(with its contained extract) are discharged simultaneously butseparately from the centrifugal bowl, and the oil and water component issubjected to an emulsionbreaking treatment. At this point, I prefer toadjust the pH value of the oil and water component to about 9 (as by theaddition of NazCOs) add a protein-coagulating agent, and heat andhydrate this component. It is then recentrifuged to separate it into oiland water phases. The separated water phase from the second centrifugingis returned to the substantially oil-free component discharged from therst centrifuging, and sugar is added to these combined materials forproduction of a chocolate syrup. The oil phase discharged from thesecond centrifuging is substantially pure, although it may be filteredto improve its quality for commercial use as cocoa butter.

The new process enables an economical and practically complete recoveryof the cocoa butter from the starting material, and in a continuousmanner. Also, the process is advantageous with respect to the qualityand yield of the cocoa flavoring for use in making chocolate syrups. Thecombined oil-free component from the first centrifuging and water phasefrom the second centrifuging include substantially all of the waterutilized in the process and yet form a concentrated extract which can beused directly for chocolate syrup production. By hydrating the oil andwater component prior to the second centrifuging, the added water servesto wash the oil and also to dilute the sludge or concentrated cocoasolids obtained from the first centrifuging.

A further feature of the invention resides in the manner of effectingthe separation of the oil from the cocoa mixture in the firstcentrifuging. Preferably, this separation is made in a centrifuge of thetype having outlet nozzles in the outer periphery of the centrifugalbowl, for discharging separated solids in jets, and separate outlets fora light component (oil) and an intermediate component (extract). Inother words, the substantially oil-free component is separated into twosub-components, the heavier of which contains a relatively highproportion of solids and is discharged as sludge through the nozzles.The lighter sub-component is mainly a watery extract of soluble cocoasolids and is discharged through the intermediate outlet. In this way,the sludge can be discharged without clogging the bowl and is impactedand broken up against the usual stationary receiver surrounding thebowl. The discharged sludge is then returned to the extract dischargedas the intermediate component, with which the water phase obtained fromthe second centrifuging also is preferably joined. This manner ofcentrifuging not only enables a higher throughput rate but also improvesthe quality of the nal cocoa avoring material. If desired, some of thedischarged sludge may be recycled to the first centrifuging, in order todecrease the water content of the discharged material. Preferably, thesludge, if recycled, is returned directly to the peripheral part of thecentrifugal bowl in the region of the discharge nozzles.

For a better understanding of the invention, reference may be had to theaccompanying drawings, in which Fig. 1 is a schematic View of a systemfor use in carrying out the process, and

Fig. 2 is a vertical sectional view of part of a centrifuge for use ineffecting a three-way separation of the cocoa mixture.

Referring to the drawings, the reference numeral I designates a steamjacketed tank for heating ltered water delivered through an inlet lineIa. The steam for heating the water is fed into the jacketed spacethrough a steam line Ib, the condensate being discharged through a pipeline Ic. Boiling water from the tank I is passed through a pipe line 2into either of two coil vats S-4. Pulverized cocoa is fed into either ofthese vats, as indicated at 6, and the boiling water from tank I ismixed with it in order to gelatinize the insoluble starch in the cocoa.Preferably, the mixture of cocoa and water is held for 20 minutes at atemperature of 185 F. in the vat 3 or 4. An enzyme, such as thediastatic enzyme produced by Pillsbury Mills and designated P73 is addedto the mixture in the vat, after cooling the mixture to a temperature atwhich the enzymatic action is not inhibited, for example, F. The enzymeis dispersed uniformly throughout the aqueous mixture of cocoa, and themixture is allowed to stand for a time interval sufcient to saccharifythe gelatinized starch, preferably about 20 minutes. Aprotein-coagulating agent, such as common salt, is then added to themixture in the coil vat.

As an example of the preferred practice of the process, the batch thusprepared in either of the vats 3 4, may consist of 1766 lbs. ofpulverized cocoa, 4500 lbs of water, 30 lbs of the above-identied P73enzyme and 120 lbs. of common salt.

After addition of the protein-coagulating agent to the mixture in thevat 3 or ll, the mixture is fed through a pipe 8, pump 9 and pipe I0 toa pair of parallel-connecting lters I I. The ltering operation II servesto remove from the cocoa mixture the coarse solids which would tend toclog the centrifugal separator in the subsequent separating operation.From the filters Il, the mixture flows through a pipe I2, a flowregulator I3 and a pipe I4 to the centrifugal separator I5. The owregulator I3 may be of any conventional type which operates to pass themixture at a uniform rate to the centrifuge I5, in spite of anyvariations in the ow rate in advance of this regulator. I have foundthat unless substantial fluctuations in the feed rate to the separator 5are prevented, the separating operation is impaired.

The centrifuge I5 is of the type which provides a three-way separationand discharge of the mixture, the heaviest separated component beingdischarged in jets through nozzles in the outer periphery of thecentrifugal bowl. A centrifuge of the De Laval AC-VO type is an exampleof such a separator. The lightest component separated in the centrifugeI5 is a mixture of oil and water, more or less emulsied and containingsome of the soluble extract of the cocoa and possibly some insolublesolids. rIhis light component is discharged from the centrifuge througha conduit I6. The component of intermediate specific gravity consistsmainly of a watery extract of the soluble cocoa solids, and it isdischarged from the centrifuge through a conduit I1. The heaviestseparated component has a relatively high content of insoluble solidsand is in the form of a sludge. It is discharged through the peripheralnozzles of the centrifugal bowl through a. discharge line I8. Theseparation in the centrifuge I5 is effected at a temperature of about180 F.

The centrifuge I5 is adjusted to give a clean separation of oil from theheavier components.

aeaaeso Thus, while the oil and water component discharged throughconduit I6 will contain some of the heavier components, the extractv andsludge discharged through the conduits II and I8, respectively, will bepractically free of oil.

The discharged extract in conduit I7 is returned to the dischargedsludge in the conduit I8 and the merged components are fed through apump I9 and pipe 20 to a coil vat 2|, where they are subjected tofurther processing to be described presently.

The oil and water component discharged in the conduit I6 is delivered bya pump 23 and a pipe 25 to one of two stainless steel, jacketed tanks 25and 25a. In the example previously specied, the amount of this componentcollected in tank 25 or 25a will be about 500 lbs. If the proportions ofoil and water being delivered to tank 25 or 25a are not approximatelyequal, then boiling water is added to the oil and water mixture so as tokeep the percentages of each approximately equal; and the pH value ofthe mixture is adjusted to 9, as by the addition of sodium bicarbonate.

A protein-coagulating agent, preferably common salt in an amount ofabout 30 lbs., is also added to the mixture in the tank 25 o-r 25a. Themixture is then cooled to about 160 F. By means of ie above-describedtreatment in the tank 25 or the oil and water emulsion is broken and themixture is prepared for the second centrifuging operation.

From the holding tank 25 or 25a, the oil and water mixture is fedthrough a pipe 21, pump 28 and ow regulator 29, to a centrifuge 30. Thiscentrifuge is of the type providing a two-way separation and dischargeof the mixture. For example, it may be a De Laval centrifuge of the No.720 type. In the centrifuge 30, the mixture is separated into a purifiedoil component and a water component, which are continuously butseparately discharged through pipe lines BI and 3Ia respectively. Thedischarged cocoa butter oil has a high degree of purity, but it may besubjected to further purication by passing, it through a pump 32 into atank 33 where it is mixed with about 1 of anhydrous calcium oxide and 2%of lter acid, the oil then being passed through a pump 34 and a filterpress 35. The puried cocoa butter oil discharged from the filter 35 isin a form suitable for commercial use.

The water component separated in the second centrifuge Sil contains someof the watery extract separated with the oil in the rst centrifuge I5.This water component is continuously discharged from the centrifuge 3Qthrough the pipe line 3Ia and is returned by a pump 3l and conduit 38 tothe sludge and. extract components in the pipe 2D. Thus, the materialcollected in the coil vat 2| consists of the two heavier componentsseparated in the rst centrifuge I5 and the water component separated inthe second centrifuge 30. This material is in condition to be useddirectly in the production of a chocolate syrup. For this purpose,liquid sugar is added to the cocoa avoring in the vat 2l through a pipeline 39, along with the other ingredients conventionally used for suchsyrups. The chocolate syrup may then be discharged froin the coil vat 2Ithrough pipeline 40.

Referring now to Fig. 2, a suitable form of the first centrifuge I5comprises a centrifugal bowl 42 mounted on a, driving spindle 43 forrotating the bowl on a vertical axis. The spindle 43 extends into a nave44 at the central part of the bowl. The cocoa mixture is delivered bythe pipe It into the upper end of a hollow tubular shaft 45 in the bowl.It then flows downwardly through passages 45d', to the. bottoni portionQi the bowl, from which it passes upwardly through` distributing holes,45d in a set of conical discs 46. located in the separating chamber ofthe bowl. In the spaces between the discs 4t., the oil in the cocoamixture and some of the water are separated as a lighter component andpass inw-ardly to vertical passages B'l formed between the tubular shaft45 and the inner edges of the conical discs. The oil andA water mixturethen passes upwardly through passages 4'1 and is discharged from thebowl through an annular outlet #.8v surrounding the tubular shaft 45.The` discharged oil and water component is collected in a. stationaryreceiver 49, surrounding the upper part of the bowl and delivered to theconduit I6 (Fig. l)

The remainder of the mixture separated between the discs 45 passesoutwardly into a peripheral region of the bowl chamber outside thediscs, where it is further separated into the intermediate componentcomprising mainly the watery extract of soluble Cocoa solids, and aheavy coinponent or sludge. The extract is discharged from theseparating chamber through passages 5I) formed between the bowl top anda top disc 5I, the extract nally escaping from the bowl throughanannular intermediate outlet 52 located between theY bowl neck and thetop disc 5I. stationary receiver 53 collects the discharged extract orintermediate component and delivers it to the conduit Il (Fig. l). Theseparated sludge or heavy component is discharged in jets throughnozzles 5din the outer periphery or" the bowl. Due to the jet action ofthe sludge dis.- charged through the nozzles, clogging of the bowl bythe sludge is prevented. The sludge from the nozzles is collected in astationary receiver 55, from which it passes4 through an outlet 55 tothedischarge conduit I 3 (Fig. l). The impact of the sludge iets againstthe stationary receiver 55 serves to break up the sludge particlesbefore they are` merged with the extract component in the line I5.

In order to enable the use of larger discharge nozzles 513 and therebyreduce any tendency for the sludge to clog these nozzles, it may bedesirable to re-circulate some of the sludge to the separating chamberin the vicinity of the nozzles 5d. That is, some of the sludge may bewithdrawn from the discharge conduit I8 by a pump 58 (Fig. 1) and forcedthrough a pipe 59 into a central internal recess 42a in the bowl (Fig.2). From the recess 42a, the recycled sludge is delivered by centrifugalforce through radial tubes @il leading to the region of or into thenozzles 54. In this way, the recycled sludge serves to hold back thelighter components and prevent their discharge through the nozzles 54,which can tlelrefore be larger than would otherwise be possi e.

The iiow regulators I3 and 29 may, if desired, be in the form of surgetanks which feed th respective centrifuges I5 and 30 by gravity, so asto provide a continuous and easy flow. By the use of the two holdingtanks 25 and 25a, the demulsii'ication of the oil and water mixture fromcentrifuge I 5 can be effected continuously, it being understood thatrst one holding tank and then the other feeds the second centrifuge 30.

I claim:

l. In the treatment of cocoa to produce cocoa n butter and asubstantially fat-free cocoa flavoraqueous mixture of the cocoa infinely divided form to a temperature sufficient to gelatinize theinsoluble starch content of the cocoa, reducing said temperature andsaccharfying the gelatinized starch by treating the mixture with anenzyme, coagulating protein in the mixture, feeding the mixture into alocus of centrifugal force and there separating it into an oil and Watercomponent and a substantially oil-free component, simultaneously butseparately discharging said components from the locus, at least partlybreaking the emulsion of the oil and water component and recentrifugingit to separate it into oil and Water phases, and returning said waterphase t said substantially oil-free component and adding sugar theretofor production of a chocolate syrup.

2. A method according to claim l, comprising also the step of hydratingthe oil and Water component, prior to said recentrifuging, to Wash theoil and provide additional Water in said returned phase for the syrup.

3. A method according to claim l, comprising also adjusting the pH valueof the discharged oil and Water component to about 9 prior to saidrecentrifuging.

4. A method according to claim 1, comprising also the step of filteringsaid oil phase to remove residual solids therein.

5. A method according to claim 1, in Which sodium bicarbonate and sodiumchloride are added to the discharged oil and Waer component and the pHvalue thereof is adjusted to about 9, prior to said recentrifuging.

6. A method according to claim l, in which the discharged oil and watercomponent is mixed with water, heated to an emulsion-breakingtemperature, salted, and adjusted to a pH value of about 9, prior tosaid recentrifuging.

7. A process according to claim 1, comprising also the steps ofcentrifugally separating the substantially oil-free component in saidlocus into sub-components comprising, respectively, sludge and a wateryextract of soluble chocolate solids, discharging the sludge in jetsthrough the outer periphery of the locus While separately dischargingsaid extract from the locus, and returning discharged sludge as Well assaid Water phase to the discharged extract.

8. A method according to claim 1, in which said aqueous mixturecomprises about 2.5 parts' of water to 1 part of powdered cocoa byweight, said enzyme being diastatic and added in an amount of about 1-2%by Weight of the cocoa, the pro,- tein-coagulating agent being sodiumchloride added in an amount of about 6-7% by Weight of the cocoa.

9. In the treatment of cocoa to produce cocoa butter and a substantiallyfat-free cocoa flavoring, the method which comprises heating an aqueousmixture of the cocoa in nely divided form to a temperature sufficient togelatinize the insoluble starch content of the cocoa, reducing saidtemperature and saccharifying the gelatinized starch by treating themixture with an en- Zyme, coagulating protein in the mixture, feedingthe mixture into a locus of centrifugal force and there separating itinto an oil and water` component as a light constituent, sludge as aheavy constituent, and watery extract of soluble chocolate solids as anintermediate constituent, discharging the sludge in jets through theouter periphery of said locus while separately discharging the extractand the oil and Water component from the locus, returning dischargedsludge to the discharged extract and adding sugar thereto for productionof a chocolate syrup, and at least partly breaking the emulsion of thedischarged Water and oil component and recentrifuging it to separate itinto oil and Water phases.

l0. A method according to claim 9, comprising also the step of lteringsaid mixture after said gelatinizing and saccharifying operations butprior to feeding the mixture into the locus of centrifugal force.

1l. A method according to claim 9, comprising also the step ofcontinuously recirculating part of the discharged sludge to theperipheral part or said locus.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 571,238 Pieper Nov. 10, 1896 1,650,356 Hocker Nov. 22, 19271,892,449 Dengler Dec. 27, 1932 2,287,444 Morgenthaler June 23, 19422,515,794 Palmer July 19, 1950

1. IN THE TREATMENT OF COCOA TO PRODUCE COCOA BUTTER AND A SUBSTANTIALLYFAT-FREE COCOA FLAVORING, THE METHOD WHICH COMPRISES HEATING AN AQUEOUSMIXTURE OF THE COCOA IN FINELY DIVIDED FORM TO A TEMPERATURE SUFFICIENTTO GELATINIZE THE INSOLUBLE STARCH CONTENT OF THE COCOA, REDUCING SAIDTEMPERATURE AND SACCHARIFYING THE GELATINIZED STARCH BY TREATING THEMIXTURE WITH AN ENZYME, COAGULATING PROTEIN IN THE MIXTURE, FEEDING THEMIXTURE INTO A LOCUS OF CENTRIFUGAL FORCE AND THERE SEPARATING IT INTOAN OIL AND WATER COM-